There are many problems which surround the laying of plastic pipe in the ground, and particularly the connection of house service lines to a main. Natural gas services now conventionally utilize thermoplastic pipe. When a new house or other building service is to be attached, a trench is dug from the building to the main where the attachment is to take place, and a T-connection or similar fitting is connected to the main to feed the service line. The attachment of the T-fitting often has to be done in adverse conditions. Firstly the connection must be made at the bottom of a trench, which may be dark and difficult of access. In winter, the workman would typically wear gloves, and would be unwilling to remove the gloves for certain fine operations which must be done manually. Because of the cramped quarters at the bottom of the trench, it is difficult for the installer to ascertain precisely the degree of pressure that must be held both for the heating step and for the welding step. With time, experience teaches the installer how to carry out these operations, but the inexperienced workman is often not able to complete the installation job in a satisfactory manner.